The present invention relates to measurement devices and in particular to flow probes and mechanisms for placement and removal of implantable medical devices.
Flow probes are used for measuring the flow of fluid within a conduit. There are many applications in clinical and research medicine in which measurement or estimation of fluid flow within a conduit is desirable. For example, the monitoring of blood flow in a vessel provides information that may be used in a variety of applications. Some of these applications include the discovery and assessment of compounds during the development of various drugs or assessing the hemodynamic status of patients for the purpose of guiding therapies or care. An additional application is the research of the various factors that may impact the hemodymanic status where the blood flow parameter is one of the indicators. For many applications implantable devices such as flow probes are surgically implanted in animals or humans. The placement of flow probes and other implantable devices is a difficult task as the devices are small and precision in placement is vital.
When placing flow probes for measurement of fluid flow within a conduit the orientation of the probe with respect to the conduit is essential. For example, some transit time measurement devices are dependent upon the angle of an ultrasound path with respect to fluid flow. Some flow probes completely encircle or partially encircle the conduit to be monitored and have to be sized properly so as to reduce measurement errors. If the flow probe is not positioned properly measurement errors can result. For example, when a conduit is smaller than the conduit size that a flow probe was designed for, the probe can rotate and/or tilt on the conduit, causing an error in the angle that the ultrasound beam intersects the fluid flow, resulting in an error in the flow measurement.
Flow probes vary in size for the respective application. Currently, individual probes are designed to operate optimally on a single conduit size to reduce the risk of measurement errors caused by ultrasound angle tilting errors. As a result, probes of various sizes must be produced to meet the wide range of applications. The end user has to stock multiple sizes of probes to meet the range of anticipated applications, which is expensive for both the manufacturer and customer.
Accurate placement and, once implanted, proper orientation of flow probes may be difficult to accomplish. Retrieval of implanted devices is also very difficult. Devices such as flow probes are often located in difficult to reach places and accessing the device for removal becomes challenging. Improperly grasping a device with pincers or tweezers may damage the device. In the case of having a memory device that stores calibration or other information integral with the flow probe, the memory device may be damage and information lost due to improper handling with surgical instruments. In other scenarios the device may break up and pieces of the device may be lost within the body cavity.
The above mentioned problems with medical devices and flow probes are addressed by one or more embodiments of the present invention and will be understood by reading and studying the following specification.
According to one aspect of the present invention an apparatus is provided. The apparatus includes a sensor housing adapted for mounting one or more sensors. The apparatus further includes one of a plurality of different sized coupling members which includes one or more windows for the one or more sensors. The sensor housing is adapted to couple with the one of a plurality of different sized coupling members to accommodate various sized conduits. In one embodiment, the sensor is a transducer and the windows are acoustically transparent windows. Other sensors may be used in the present sensor housing.
According to another aspect of the present invention a flow probe is provided. The flow probe includes one or more transducers and a sensor housing adapted for mounting the one or more transducers. The flow probe also includes one of a plurality of different sized coupling members which includes one or more acoustically transparent windows for the one or more transducers. The sensor housing is adapted to couple with the one of a plurality of different sized coupling members to accommodate various sized conduits.
According to an alternate aspect of the present invention an implantable medical device is provided. The implantable medical device includes a first body. The first body includes positioning elements, such as dimples, for placement and retrieval of the implantable medical device.